Tracking the migration of the Indian continent using the carbonate clumped isotope technique on Phanerozoic soil carbonates.

Approximately 140 million years ago, the Indian plate separated from Gondwana and migrated by almost 90° latitude to its current location, forming the Himalayan-Tibetan system. Large discrepancies exist in the rate of migration of Indian plate during Phanerozoic. Here we describe a new approach to paleo-latitudinal reconstruction based on simultaneous determination of carbonate formation temperature and δ(18)O of soil carbonates, constrained by the abundances of (13)C-(18)O bonds in palaeosol carbonates. Assuming that the palaeosol carbonates have a strong relationship with the composition of the meteoric water, δ(18)O carbonate of palaeosol can constrain paleo-latitudinal position. Weighted mean annual rainfall δ(18)O water values measured at several stations across the southern latitudes are used to derive a polynomial equation: δ(18)Ow = -0.006 × (LAT)(2) - 0.294 × (LAT) - 5.29 which is used for latitudinal reconstruction. We use this approach to show the northward migration of the Indian plate from 46.8 ± 5.8°S during the Permian (269 M.y.) to 30 ± 11°S during the Triassic (248 M.y.), 14.7 ± 8.7°S during the early Cretaceous (135 M.y.), and 28 ± 8.8°S during the late Cretaceous (68 M.y.). Soil carbonate δ(18)O provides an alternative method for tracing the latitudinal position of Indian plate in the past and the estimates are consistent with the paleo-magnetic records which document the position of Indian plate prior to 135 ± 3 M.y.